Written by: Martijn Redegeld
Rice, pasta or oatmeal, just a few classic examples of foods that are often eaten prior to important sporting performances. But sports drinks, energy gels or a banana during exercise are also common guests. What do all these products have in common? They are rich in carbohydrates! This nutrient can be responsible for a fantastic feeling on the bike, but also for the dreaded bonk. You can read in this blog how many carbohydrates you need during your exercise.
In summary:
- Carbohydrates are the most important fuel during exercise, especially when the intensity increases.
- Due to the limited storage capacity in the body, we must continue to replenish carbohydrates during exercise if duration and/or intensity increase.
- During exercise lasting up to 60 to 75 minutes, drinking water is sufficient (if the glycogen stores are well filled beforehand). Regularly rinsing your mouth with a carbohydrate-rich drink can improve your performance.
- During exertion lasting 75 to 150 minutes, it is recommended to consume 30 to 60 grams of carbohydrates per hour. This is equivalent to 1 to 2 Amacx products per hour.
- During exercise lasting longer than 150 minutes, it is recommended to aim for higher intakes with a maximum of 90 to 120 grams of carbohydrates per hour. This is equivalent to 2-4 Amacx products per hour.
The importance of carbohydrates
Carbohydrates, together with fats, are the most important source of fuel during exercise. When the duration or intensity of an exercise increases, and with it the body's energy requirements, the importance of carbohydrates becomes greater and greater. However, there is one crucial point to consider: the storage capacity of this fuel in the body is limited. This nutrient is stored in our body in the form of glycogen, mostly in the muscles and to a lesser extent in our liver. This glycogen supply is, as it were, the body's fuel tank.
Avoiding the hunger knock
These limited storage options mean that filling up, maintaining and replenishing before, during and after strenuous exercise is a very delicate matter. Suboptimal intake at any of these stages can negatively affect your performance and/or recovery. When you have fully filled your glycogen tank before a training session or competition, this will suffice for about 75 to 90 minutes of exercise. However, when the intensity of the exercise is high, the glycogen supply can be depleted much faster (e.g. during a race on Zwift or intensive interval training). When that happens, the well-known and dreaded ‘bonk’ occurs: you will have to abruptly end your exercise because you have simply reached the bottom of your fuel tank.
Eating and drinking carbohydrate-rich products during exercise ensures that the consumption of your own glycogen stores is slower. With a good nutrition plan, you can avoid getting beat by hunger. And perhaps even more important: by maintaining a sufficient carbohydrate supply in the body, you can continue to deliver a higher quality until the end of the training, which is also accompanied by better focus and a more pleasant feeling.
Carbohydrates and short efforts
Always make sure you are well prepared for your training or competition. If your exercise lasts 60 to 75 minutes, it is sufficient to fill your glycogen stores well beforehand and only drink water during the exercise. The only added value that carbohydrates can offer during such a relatively short period of exertion is what is known as ‘mouth rinsing’ with a sugary drink. Various studies show that rinsing your mouth a few times (5 to 10 seconds) improves performance (e.g. with isotonic sports drink or soft drink). This is because a signal goes directly from the mouth to the brain that ‘tells’ it that new energy is on its way. This then suppresses the feeling of tiredness and the energy already stored in the body is released a little faster. This ultimately makes your effort easier and faster.
If your training or competition lasts longer than 60 to 75 minutes, it is advisable to aim for 30 to 60 grams of carbohydrates per hour. This is equivalent to 1 to 2 Amacx products per hour (e.g. 1 bottle of Isotonic Energy Drink + 1 Energy Oat Bar). Start with this from the very first hour and continue to consume it evenly throughout the entire training session. This will ensure that you do not reach the bottom of your glycogen stores (your ‘fuel tank’). If your exercise lasts longer than 2 to 2.5 hours, it is advisable to increase carbohydrate intake even further to 90 or even 120 grams per hour. With these high intakes, it is crucial to select products with the right carbohydrate ratio. It is crucial to train these high intakes regularly and increase them gradually.
Marathon runner (70kg) (goal = ± 210 grams of carbohydrates)
| Item | Carbohydrates (g) |
|---|---|
| 4 white bread rolls with jam, syrup, or sprinkles | 135 g |
| Bowl of fruit yogurt (200g) | 25 g |
| 30 grams of cornflakes | 25 g |
| 1 glass of fruit juice (200ml) | 25 g |
| Total | 210 g |
Don't forget that in addition to duration, the intensity of the effort also plays an important role in your carbohydrate needs. Is interval training planned or do you plan to spend an afternoon riding your bike at a brisk pace? Then always aim for the higher intake within the above ranges.
